import { asyncRouterMap, constantRouterMap } from '@/router';

/**
 * 通过meta.role判断是否与当前用户权限匹配
 * @param {Array} roles 用户权限
 * @param {Object} route 路由
 */
function hasPermission(roles, route) {
  if (route.meta && route.meta.roles) {
    return roles.some(role => route.meta.roles.indexOf(role) >= 0);
  } else {
    // 当前路由不需要验证权限，直接通过
    return true;
  }
}

/**
 * 递归过滤异步路由表，返回符合用户角色权限的路由表
 * @param asyncRouterMap 需要验证权限的路由
 * @param {Array} roles 用户拥有的权限
 */
function filterAsyncRouter(asyncRouterMap, roles) {
  return asyncRouterMap.filter(route => {
    if (hasPermission(roles, route)) {
      if (route.children && route.children.length) {
        route.children = filterAsyncRouter(route.children, roles);
      }
      return true;
    }
    return false;
  });
}

const permission = {
  state: {
    routers: constantRouterMap,
    addRouters: []
  },
  mutations: {
    SET_ROUTERS: (state, routers) => {
      state.addRouters = routers;
      state.routers = constantRouterMap.concat(routers);
    }
  },
  actions: {
    GenerateRoutes({ commit }, data) {
      return new Promise(resolve => {
        const { roles } = data;
        let accessedRouters;
        if (roles.indexOf('admin') >= 0) {
          // 权限无限大
          accessedRouters = asyncRouterMap;
        } else {
          accessedRouters = filterAsyncRouter(asyncRouterMap, roles);
        }
        commit('SET_ROUTERS', accessedRouters);
        resolve();
      });
    }
  }
};

export default permission;
